Printing blanket for offset work



May 5, 1931. F. w. ADsn' ET AL PRINTING BLANKET FOR OFFSET WORK Filed Jan. 16, 1926 fatenteol May 5, 193i FRANK `W. ADST' .AED THOMAS W'. HICKS, OF MNNEAPOLIS, MINNESOTA RNTTNG- BLATKET FOB. OFFSET 'WRK Application filed January 16, 1926. Serial No. 81,685.

Our invention relates to the making of Aprinting or offset blankets which are used to transfer the printing ink of any color directly on to the nished sheet so that the printing blanket has a uniform surface about the cylindrical roll which carries the blanket over the entire printing roll. .This permits odset printing to be accomplished Without any break in the cylinder so that the entire surface of the cylinder can be used for printing, thereby providing a very valuable means of offset printing and color work which is most desirable.

Heretofore printing blankets have been used on offset presses by taking a blanket which is made of a rubber composition and clamping its ends over the cylinder which carries the blanket. This means requires the clamping of the ends of the blanket tightly so that the blanket will not slip in printing, otherwise the offset work would be spoiled. With such a means of printing with a blanket and a sheet which is clamped about the cylinder it can be readily comprehended that it is not altogether desirable for various kinds of work and particularly where it is desired to use .the entire surface of the cylinder to oset in the press. Our invention accomplishes these results by providing an oset printing surface uniform about the entire outer surface of the cylinder.

A feature of our invention resides in electrodepositing the desired rubber composition directly on to the shell of the cylinder which may be of metal or any other suitable material, and by also electroplating the rubber composition, the rubber on wood or cloth to provide the printing cylinder with a blanket of the proper rubber consistency to provide a uniform offset printing surface on the entire outer surface of the cylinder. Our invention includes the method of making printing blanket cylinders for offset printing work which is desired to be used for printing different colors vof ink on to the sheet to be printed as it passes through the printing machine or offset press. This method includes the electrodepositing of rubber directly on the metal of the shell of the cylinder or on a wood orcloth base over the shell of the cylinder as may be most desired.

With our invention it is possible to provide a printin blanket cylinder by electrodepositing ru ber or any other suitable means on to the metallic surface of the shell of the printing cylinder to provide a layer of rubber which may Abe vulcanized and thus providing an electro-plated rubber surface having even more strength than a rubber surface prepared in the ordinary methods. This is very desirable for printing blankets because in offset printing with a printing blanket the surface of the same n must be firm so as to transfer the printing or coloring matter from the plate or type on to the sheet as it passes beneath the printing blanket. portant that the blanket be firm and imvmovable when in operation in relation to the cylinder carrying the blanket. In the old method of blankets for offset printing the least movement of the blanket causes various colors to be shifted out of line and thus spoils the delicate offset printing very easily by the shifting of the blanket. With our blanket formed integral with the shell of the cylinder and firmly fixed thereto and being continuous about the same, we can give perfect registry of the Various colors` in a very desirable manner.

Other features and objects of the invention will be more fully and clearly set forth in the specification and claims.

To assist in describing our method of making our printing blanket for offset printing we have desired to set forth in the drawings diagrammatically figures which will more clearly describe the invention and which are as follows:

Figure l is a diagrammatic side View of our printing blanket formed continuously about the printing cylinder.

Figure 2 is a cross section on the line 2 2 n of the same.

In carrying out our method of making our printing blankets A we employ a cylinder core or body E which is carried on the shaft C in the ordinary manner to support the Further, it is very im-A cylinder E in an oifset printing press or other printing means so that the cylinder may be freely rotated in the operation of printing.

Our printing blanket is very desirable for rotary printing presses and olfset printing presses as it gives a larger Work surface on the printing blanket and in fact provides a continuous Work surface over the entire cylinder.

In carrying out our method of making rubber printing blankets by electrodepositing rubber We desire to set forth that it is desirable to electrodeposit the rubber on to a continuous cloth which may be fixed to a shell such as D.

In this form of our invention the cloth 10 is of a continuous nature about the cylindrical surface of the shell D and may be attached to the shell D or otherwise held so as to form a cylindrical fabric bod on to which the rubber blanket A is e ectrodeosited to provide a continuous printing blanket about the surface of the cylinder, as illustrated in Figure 1.

In Figure l, the printing cylinder supporting the printing blanket A is provided with a core or bod portion E whichv is carried on the shaft In this construction the shell D is removable from the core E and is adapted to support the cloth or textile material 10 to which the rubber blanket A is deposited and firmly fixed so as to form an integral part therewith.

The shell D is removable from the core E with the blanket A thereabout, thus providing a construction which permits the printing blanket A to be removed from the cyl-y inder Eend permitting it to be replaced b a similar removable printing blanket which would be formed on' a similar shell D.

This form of removable printing blanket having a continuous outer cylindrical printing, surface is very desirable as it permits the printing cylinder or blanket to be readily removed at any time or inter-changed if it is desired.

Our means of providing a ,cylindrical continuous'printing blanket A about the entire surface of the printing cylinder is a means of fulfilling a long felt want in the printing art and while we have described a particular means of carr ing out our method We desire to have it understood that the drawings are only diagrammatic and that the formation of the printing blanket may be accomplished by other means than those above set forth Within the scope of the following claims.

We claim:

l.V A printing cylinder including, a removable cylindrical shell portion and a printing film deposited around the same to provide a covering of ink receivingcomposition adaptable of transferring `the ink in an 0H- set manner.

2. A printing cylinder including, a cylindrical shell portion and a film electroplated on to said shell in a manner to form the printing surface of said cylinder to provide an offset' means for receiving and transferring ink. i

3. A printing cylinder including, a removable cylindrical shell, and means de- 

